The 10 Youngest Richest, From Sergey Brin to Mark Zuckerberg (Photos)

Mark Zuckerberg has a lot of responsibility on his shoulders for a 27-year-old. But there’s at least one thing he hasn’t had to worry about for years: the state of his bank account.

With market-capitalization estimates as high as an absurd $75 billion to $100 billion, Facebook’s initial public offering likely added several billion dollars to Zuckerberg’s net worth (on paper, anyway). Zuckerberg is young, and he is very, very rich—but he’s not the only one.

We compiled this ranking of the youngest richest people in America using data from the Securities and Exchange Commission and the most recent Forbes magazine estimates.